Ge Engine Focus Of Faa Safety Proposal

January 04, 2001|By SUSAN E. KINSMAN; Courant Staff Writer

Another potential engine-failure problem with an early generation of General Electric's popular CF6 engine has prompted federal regulators to propose a new safety rule that could affect 1,730 of the engines worldwide.

The proposed rule -- expected to become law after a public comment period expires Jan. 23 -- would require operators to install redesigned air ducts and related hardware in the high-pressure compressor of GE's CF6-50 engine, as GE recommended in May.

The Federal Aviation Administration said there have been 51 reports of the air duct cracking, and in six cases the failure caused the fan shaft to separate, causing blades from the low-pressure turbine to be blown through the engine's cowling, or protective covering.

There have been no injuries, the FAA said, but the problem is a concern because "air duct failures were first documented in 1976, [and] two subsequent redesigns have failed to correct the cracking problem."

The engine, introduced in the mid-1970s, is used primarily to power DC-10 aircraft, GE said. The FAA estimates that there are 1,730 engines of that design in the worldwide fleet, including 469 in the United States. The potential cost of the repairs to U.S. operators is nearly $18 million.

The pending FAA order is not related to equipment problems that caused other failures of the CF6-50 and GE's later-generation CF6-80C2 engine, which were the focus of published reports Tuesday.

The later engine was introduced in 1985, and is the most popular for widebody aircraft, with about 3,000 in use, said Richard L. Kennedy, a spokesman for GE Aircraft Engines in Cincinnati.

General Electric and the FAA said the safety issues posed by the compressor spools and high-pressure turbine discs on the CF6-80C2 and low-pressure turbine nozzles on the CF6-50 are being addressed by stepped-up inspections and equipment replacement where necessary under other FAA orders.

The problems are also not expected to affect GE's earnings because the company has adequate reserves to cover the contingencies, Kennedy said.

"It is important to note that while these are safety issues, it doesn't necessarily mean the planes are unsafe. Even an uncontained engine failure will not make a plane fall out of the sky,'' said Les Dorr, an FAA spokesman.

"Any engine that is on any civil jet aircraft is extremely reliable," Dorr said. For example, GE engines that are approved for twin-engine long-range flight have 0.02 shutdowns for every 1,000 engine hours, he said.

"Most pilots will go through their entire career without experiencing an engine shutdown," Dorr said.

General Electric's engine problems are in no way unique. The FAA issues, on average, about 400 safety orders, called "airworthiness directives," every year on all classes of aircraft and engines.

For example, 51 orders have been issued by the FAA since 1970 on Pratt & Whitney's JT8D series turbofan engines, said Jim Peters, a spokesman for the FAA's regional office.

Unlike manufacturer recommendations, the FAA orders carry the force of law and require operators to meet the terms and conditions to bring the aircraft into compliance with aviation regulations.

The orders are directed at design, manufacturing and maintenance problems that emerge during operation that could affect safety.

Although negative publicity about its engines caused General Electric's stock price to fall Tuesday, it rebounded Wednesday, buoyed by the market upswing from the cut in interest rates and by a number of financial analysts who reiterated their ratings on GE stock as a buy or strong buy.